Today I have learnd about Looping over 2D array

I had time for 6 hours of coding today, and it has been some hard 6 hours. I'm a really poor student. One of the reasons I picked electrician as a profession, is that it was easy to get into the school. Going to a school filled with poor students did not help, so sitting down and learning something over a long period of time takes me a long time.

Today was about arrays and 2D arrays. I still don't fully understand what it means, but now I get the general idea of how it works.
This is what the 2D array has been used for, finding the sum of the numbers.